Resource recovery from excess sludge by subcritical water combined with magnesium ammonium phosphate process

2006 ◽  
Vol 54 (9) ◽  
pp. 81-86 ◽  
Author(s):  
M. Arakane ◽  
T. Imai ◽  
S. Murakami ◽  
M. Takeuchi ◽  
M. Ukita ◽  
...  

The amount of excess sludge produced in municipal wastewater treatment plants in Japan is increasing every year as the urban population increases. Phosphorus in excess sludge could be a potential phosphorus resource since at present, phosphate rock is being exhausted all over the world. Every year, Japan imports large quantities of phosphorus from abroad but much is discharged as excess sludge. Therefore, the solubilization process, one method of recovering phosphorus from sludge, could be a promising solution. In this study, a subcritical water process, a new technology that solubilizes sludge under subcritical conditions, was applied before the phosphorus in sludge was recovered with the magnesium ammonium phosphate (MAP) process. As a result, the solubilization rate of excess sludge achieved approximately 80% and about 94–97% of the phosphorus could be recovered.

2005 ◽  
Vol 16 (4) ◽  
pp. 309-317
Author(s):  
Mitsuhiro Arakane ◽  
Tsuyoshi Imai ◽  
Sadaaki Murakami ◽  
Masami Takeuchi ◽  
Masao Ukita ◽  
...  

1994 ◽  
Vol 30 (12) ◽  
pp. 415-424 ◽  
Author(s):  
U. Austermann-Haun ◽  
C.F. Seyfried

In the western part of Germany there are 77 full scale anaerobic treatment plants treating industrial wastewater. The ISAH (Institut für Siedlungswasserwirtschaft und Abfalltechnik at the University of Hannover) is or was involved in the investigations, the design and/or operation of 14 of these plants. Some industries (sugar beet, starch, pectin, brewery, vegetable) with their special problems with treating their wastewater anaerobically are described. Experiences of how to handle high nitrate concentrations, to treat a mixture of several industrial wastewaters, to prevent or handle lime, magnesium ammonium phosphate (MAP) or aluminium precipitations are reported. The first municipal wastewater treatment plant combined with a separate anaerobic stage to treat a wastewater mixture of several small factories is described. Something very special about this plant is the construction of the acidification tank. Using the “teapot effect” to enrich the solid material in the centre of the bottom, the solids can be taken from the bottom of the tank and pumped to the municipal sludge digester.


2005 ◽  
Vol 3 (1) ◽  
pp. 119-124 ◽  
Author(s):  
Mitsuhiro Arakane ◽  
Tsuyoshi Imai ◽  
Sadaaki Murakami ◽  
Masami Takeuchi ◽  
Masao Ukita ◽  
...  

2012 ◽  
Vol 178-181 ◽  
pp. 507-511
Author(s):  
Zhi Min Zhang

The concentration of heavy metals in excess sludge from municipal wastewater treatment plants has restricted its convertion to soil fertilizer, so it is necessary to remove the heavy metals from sludge. In this article, the effects of heavy metal removal by some mineral acids such as HCl, H2SO4, H3PO4, HNO3 were analysed, when treating excess sludge from a second sediment tank in municipal wastewater treatment plants. To improve the treatment, a combination of H2O2 and acid was also investigated. Consequently, the difference of heavy metal removal among those acids was showed. Its removal of Hg by HNO3 was better than by other acids. Lower pH enhanced the dissolving of heavy metal, yet the removal of Cr was insensitive to the pH. Aided by H2O2, the removal by the acid was enhanced. The suitable dosage of H2O2 was specially related to the solid content of sludge, pH and the acid kind.


2011 ◽  
Vol 6 (1) ◽  
Author(s):  
A. Iborra-Clar ◽  
J.A. Mendoza-Roca ◽  
A. Bes-Pií ◽  
J.J. Morenilla-Martínez ◽  
I. Bernácer-Bonora ◽  
...  

Rainfall diminution in the last years has entailed water scarcity in plenty of European regions, especially in Mediterranean areas. As a consequence, regional water authorities have enhanced wastewater reclamation and reuse. Thus, the implementation of tertiary treatments has become of paramount importance in the municipal wastewater treatment plants (WWTP) of Valencian Region (Spain). Conventional tertiary treatments consist of a physico-chemical treatment of the secondary effluent followed by sand filtration and UV radiation. However, the addition of coagulants and flocculants sometimes does not contribute significantly in the final water quality. In this work, results of 20-months operation of three WWTP in Valencian Region with different tertiary treatments (two without chemicals addition and another with chemicals addition) are discussed. Besides, experiments with a 2 m3/h pilot plant located in the WWTP Quart-Benager in Valencia were performed in order to evaluate with the same secondary effluent the effect of the chemicals addition on the final water quality. Results showed that the addition of chemicals did not improve the final water quality significantly. These results were observed both comparing the three full scale plants and in the pilot plant operation.


2003 ◽  
Vol 3 (5-6) ◽  
pp. 321-327 ◽  
Author(s):  
M. Gallenkemper ◽  
T. Wintgens ◽  
T. Melin

Endocrine disrupting compounds can affect the hormone system in organisms. A wide range of endocrine disrupters were found in sewage and effluents of municipal wastewater treatment plants. Toxicological evaluations indicate that conventional wastewater treatment plants are not able to remove these substances sufficiently before disposing effluent into the environment. Membrane technology, which is proving to be an effective barrier to these substances, is the subject of this research. Nanofiltration provides high quality permeates in water and wastewater treatment. Eleven different nanofiltration membranes were tested in the laboratory set-up. The observed retention for nonylphenol (NP) and bisphenol A (BPA) ranged between 70% and 100%. The contact angle is an indicator for the hydrophobicity of a membrane, whose influence on the permeability and retention of NP was evident. The retention of BPA was found to be inversely proportional to the membrane permeability.


1982 ◽  
Vol 14 (1-2) ◽  
pp. 121-133
Author(s):  
C Forsberg ◽  
B Hawerman ◽  
B Hultman

Experience from advanced municipal wastewater treatment plants and recovery of polluted waters are described for the last ten years in Sweden. Except in municipalities with large recipients, the urban population is served by treatment plants with combined biological and chemical treatment. Most of these plants are post-precipitation plants. Several modified operational modes have been developed in order to improve the removal efficiencies of pollutants and to reduce the costs. Results are presented on the recovery of specially investigated lakes with a lowered supply of total phosphorus and organic matter.


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